Deaerator spray nozzle and related methods

ABSTRACT

A spray nozzle assembly and hub combination for operation in a boiler feedwater deaerator is disclosed, the combination including a tubular hub capable of being affixed to a wall of a deaerator tank and a spray nozzle assembly that is removably engageable with the hub, the nozzle assembly including a nozzle body, a twist lock for retaining the nozzle body relative to the hub when the nozzle body is in a fully engaged position, and a spreader moveably coupled to the nozzle body and biased by a spreader spring against opening, the spreader is capable of moving to an open position against the spreader spring bias in response to boiler feedwater pressure to form an annular opening about the spreader, thereby enabling feedwater flow.

CROSS REFERENCE TO RELATED APPLICATION

This application is a divisional application of pending U.S. patentapplication Ser. No. U.S. 12/400,190, filed on Mar. 9, 2009. Theforegoing application is incorporated by reference herein in itsentirety.

TECHNICAL FIELD

The present invention relates to treatment of boiler feedwater, and moreparticularly to assemblies and related methods for boiler feedwaterdeaerators.

BACKGROUND

Deaerators remove oxygen and other entrained gases from the feedwatersystems of boilers. In many commercial deaerators, feedwater is sprayedfrom the top of a tank, often onto horizontal trays, and steam entersthe tank via a sparger. Feedwater, stripped of gases and preheated bythe steam, exits near the bottom of the tank.

Typical feedwater spray nozzles include a cast or fabricated body and aconical or parabolic shaped spreader. The spreader is located within acollar on the body and biased to a closed position by a spring.Feedwater pressure moves the spreader against the bias of the spring tocreate an annular opening between the spreader and the collar.

Typically, deaerator spray nozzles include flanges for bolting the bodyto the inside of the deaerator tank or are threaded into a coupling orsimilar mounting component. There is a general need for improveddeaerator spray nozzles that are more easily installed within adeaerator.

SUMMARY

A spray nozzle assembly and hub combination for operation in a boilerfeedwater deaerator includes a tubular hub capable of being affixed to awall of a deaerator tank and a spray nozzle assembly that is removablyengageable with the hub. The nozzle assembly includes a nozzle body, atwist lock for retaining the nozzle body relative to the hub when thenozzle body is in a fully engaged position, and a spreader moveablycoupled to the nozzle body and biased by a spreader spring againstopening. The spreader is capable of moving to an open position againstthe spreader spring bias in response to boiler feedwater pressure toform an annular opening about the spreader, thereby enabling feedwaterflow.

The spray nozzle assembly and hub combination may include a longitudinalshaft that is coupled to the nozzle body and a retainer that is coupledto the shaft, wherein the spreader spring is in tension between theretainer and the spreader to provide the spreader spring bias. Thespreader may contact a rim of the nozzle body when the spreader is in aclosed position. The twist lock may be actuateable at least in part bytwisting of the nozzle body relative to the hub. The twist lock mayinclude a lock spring that biases against insertion of the nozzle bodyinto the hub. The combination may include a handle that extends past anoutlet end of the nozzle assembly such that the nozzle assembly isinsertable into the hub by actuation of the handle. The twist lock mayinclude pins extending from the nozzle body and corresponding J-shapedslots in the hub such that the nozzle assembly is engageable with thehub upon (i) insertion of the pins into open ends of the J-shaped slotsagainst a lock spring bias and (ii) twisting of the nozzle assembly bymeans of the handle to move the pins to short legs of the J-shapedslots. The combination may include a lock spring in compression betweenthe nozzle body and a retaining surface on the hub while the nozzleassembly is in a fully engaged, operational position in which the pinsare biased against the ends of the short legs of the J-shaped slots. Thenozzle assembly may be engageable with the hub without tools. Thecombination may include an O-ring between the body and the hub. The bodymay include a circumferential groove in which at least a part of theO-ring is retained.

A method of installing a spray nozzle assembly into a boiler feedwaterdeaerator includes the steps of: accessing an interior of a deaeratortank, providing a spray nozzle assembly that includes a lock feature, anozzle body, and a spreader that is biased toward a closed position andopenable in response to boiler feedwater pressure at a deaerator inlet,inserting at least a portion of the spray nozzle assembly into a hubaffixed to the deaerator against bias of a spring, and twisting thespray nozzle assembly relative to the hub to engage the lock feature tosecure the spray nozzle assembly relative to the hub.

The lock feature provided in the method of installing a spray nozzleassembly into a boiler feedwater deaerator may be a pin that extendsfrom the nozzle body that engages with a corresponding groove in thehub. The groove provided in the method may be an inverted J-shape suchthat when the spray nozzle assembly is in an installed position at thecompletion of the twisting step, the spring biases the pin against anend of a short leg of the J-shaped groove. The inserting step and thetwisting step in the method may be performed by an installer's one handwithout tools. The accessing step may consist of an installer accessingthe tank interior by reaching through an access port without theinstaller's trunk entering into the tank interior.

A spray nozzle for insertion into a hub that is affixed to a wall of afeedwater deaerator tank includes a nozzle body, a twist lock forretaining the nozzle body relative to the hub when the nozzle body is ina fully engaged position, and a spreader moveably coupled to the nozzlebody and biased by a spreader spring against opening. The spreader iscapable of moving to an open position against the spreader spring biasin response to boiler feedwater pressure to form an annular openingabout the spreader, thereby enabling feedwater flow.

These and various other advantages and features are pointed out withparticularity in the claims annexed hereto and forming a part hereof.However, for a better understanding of the invention, its advantages,and the objects obtained by its use, reference should be made to thedrawings which form a further part hereof, and to the accompanyingdescriptive matter, in which there are illustrated and describedpreferred embodiments of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side cross-sectional view of a spray nozzle assembly and hubcombination for operation in a boiler feedwater deaerator.

FIG. 2 is a side view of a spray nozzle assembly and hub combination foroperation in a boiler feedwater deaerator.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

Referring to FIG. 1 to illustrate a preferred structure and function ofthe present invention, a spray nozzle assembly and hub combination 10for operation in a boiler feedwater deaerator includes a spray nozzleassembly 12 and a hub 14. The spray nozzle assembly 12 has an outlet end16, an inlet end 19, and includes a body assembly 20, a spreaderassembly 30, and a twist lock assembly 40. The hub 14 has a retainingsurface 18. The body assembly 20 includes a body 21, a longitudinalshaft 22, a spreader spring retainer 23, a handle 24, an O-ring 25, alocknut 26 a, a washer 26 b, and a cotter pin 26 c. The body 21 definesa circumferential O-ring groove 27 a and a circumferential spring groove27 b and has a rim (or collar) 28. The longitudinal shaft 22 defines acotter pin opening 29 a, and the handle 24 defines cotter pin holes 29b. The spreader assembly 30 includes a spreader 32, a spreader spring34, and a spreader bushing 36. The spreader 32 and the rim 28 of thebody 21 define an annular opening 38 when the spreader 32 is disposed inan open position. When the spreader 32 is disposed in a closed position,the spreader may be seated against the rim 28 of the body 21. The twistlock assembly 40 includes a lock spring 42, pins 44, and slots (orgrooves) 46. Each slot 46 defines a open end 47 (shown in FIG. 2) and ashort leg 48 (shown in FIG. 2). The short leg 48 of each slot 46 has anend 49 (shown in FIG. 2).

The spray nozzle assembly 12 may be used to spray feedwater into aboiler feedwater deaerator (not shown), via the annular opening 38between the spreader 32 and the rim 28 of the body 21. The hub 14 is ahub that may be used for attachment of the spray nozzle assembly 12 to aboiler feedwater deaerator. The spray nozzle assembly 12 may bereleaseably coupled to the hub 14 via the twist lock assembly 40.

The body 21 may serve as a set of surfaces (including, for example, therim 28) relative to which the spreader assembly 30 may move to sprayfeedwater into the boiler feedwater deaerator (not shown). In theembodiment shown in FIG. 1, the body 21 has a rim (or collar) 28, whichmay be used as the primary surface against which the spreader 32 restswhen disposed in a closed position. When the spreader 32 is disposed inan open position, the rim 28 may also be used to help direct the flow offeedwater out of the spray nozzle assembly 12 and into the boilerfeedwater deaerator (not shown). At least part of the rim 28 may have acorrugated shape, which may help direct the flow of feedwater out of thespray nozzle assembly 12 in a radially outward direction from the rim28, in a pattern (not shown) of at least partially discrete jets, a thinfilm, a sheet, droplets, or any other pattern that is known in the art.The rim 28 may have any number of corrugations, including 12, 20, 50, oreven 100 corrugations. In some embodiments (not shown), the rim 28 mayhave a flat shape (not corrugated), or any other shape that allowsfeedwater to flow out of the spray nozzle assembly 12. The particularshape of the rim 28 and number of corrugations will depend onperformance and design considerations of the spray nozzle assembly andhub combination 10.

In the embodiment shown in FIGS. 1 and 2, the body 21 may beapproximately cylindrical in shape. However, in other embodiments (notshown), the body 21 may have other shapes, such as square, hexagonal, orany other shape that allows the body 21 to serve the function ofproviding a rim 28 against which the spreader assembly 30 may move, aswell as allowing the twist lock assembly 40 to retain the spray nozzleassembly 12 in the hub 14.

In the embodiment shown in FIG. 1, the body 21 includes an O-ring 25,which is positioned or seated in the circumferential O-ring groove 27 a.The O-ring 25 may provide a water-resistant and pressure-resistant sealbetween the spray nozzle assembly 12 and the hub 14. The O-ring 25 maybe made from rubber or any other suitable material for water andpressure sealing that is known in the art.

In FIG. 1, the O-ring 25 is coupled to the body 21 in thecircumferential O-ring groove 27 a and one end of the lock spring 42 iscoupled to the body 21 in the circumferential spring groove 27 b.However, in other embodiments (not shown), the O-ring 25 and one end ofthe lock spring 42 may both occupy a single circumferential groove. Inother embodiments (not shown), the O-ring 25 may be replaced by asealing mechanism of another type or having another shape. For example,in one embodiment, there may be multiple O-rings 25 positioned inmultiple respective circumferential O-ring grooves 27 a. In anotherembodiment, the outer surface of body 21 may be coated with a sheet ofrubber or another flexible material that is capable of creating awater-resistant and pressure-resistant seal between the body 21 and thehub 14, or the outer surface of body 21 may have circumferential ribsmade of rubber or another flexible material that is capable of creatinga water-resistant and pressure-resistant seal between the body 21 andthe hub 14.

In the embodiment shown in FIG. 1, the longitudinal shaft 22 is attachedto the body 21 via the locknut 26 a and the washer 26 b. Thelongitudinal shaft 22 may be threaded so that the locknut 26 a may bescrewed onto the longitudinal shaft 22. In other embodiments, any othersuitable mechanism known in the art may be used to removably orpermanently attach the longitudinal shaft 22 to the body 21, includingwelding, screws, and a cotter pin.

The spreader spring retainer 23 may be attached to the handle 24 via anysuitable mechanism known in the art that may be used to removably orpermanently attach the spreader spring retainer 23 to the handle 24,including welding, bolting, and screws. In some embodiments (not shown),the spreader spring retainer 23 may be formed in a continuous piece withthe handle 24 (e.g., a single casting). In the embodiment shown in FIG.1, the spreader spring retainer 23 may remain fixed relative to body 21,which may increase the potential energy in the spreader spring 34 whenthe spreader 32 is disposed in an open position (closer to the spreaderspring retainer 23), relative to the lower potential energy in thespreader spring 34 when the spreader 32 is disposed in a closedposition.

The handle 24 may be attached to the body 21 via the longitudinal shaft22. In the embodiment shown in FIG. 1, the handle 24 is attached to thelongitudinal shaft 22 using the cotter pin 26 c, which is preferablypress-fitted through two cotter pin holes 29 b in the handle 24 and thecotter pin opening 29 a in the longitudinal shaft 22. In otherembodiments, any other suitable mechanism known in the art may be usedto removably or permanently attach the handle 24 to the longitudinalshaft 22, including welding, bolting, and screws. The handle 24 may beof an appropriate size and thickness to allow a human operator toeffectively grasp the handle 24 so that the handle 24 may be used totwist the spray nozzle assembly 12 onto the hub 14.

Although in the embodiment shown in FIG. 1, the handle 24, spreaderspring retainer 23, longitudinal shaft 22 and body 21 are separatecomponents, in other embodiments (not shown), two or more of the handle24, spreader spring retainer 23, longitudinal shaft 22, and body 21 maybe made of a single-piece construction (e.g., a single casting).

In the embodiment shown in FIG. 1, the spreader assembly 30 may allowthe spreader 32 to actuate between being disposed in a closed position,disposed against the rim 28, and being disposed in an open position,spaced apart from the rim 28 and defining an annular opening 38.

As can be seen in FIG. 1, the spreader 32 may be attached to a spreaderbushing 36 that allows the spreader 32 to slide along the longitudinalshaft 22 in an axial direction. The spreader bushing 36 may be made fromplastic, Teflon, a metal such as steel or aluminum, or any othersuitable material for water and pressure sealing that is known in theart, while allowing the spreader bushing 36 to smoothly slide back andforth, preferably without lubricant, along the longitudinal shaft 22.The spreader bushing 36 may be attached to the spreader 32 via anysuitable mechanism known in the art that may be used to removably orpermanently attach the spreader bushing 36 to the spreader 32, includinga press-fit, welding, bolting, and screws. In some embodiments (notshown), the spreader bushing 36 may be formed in a continuous piece withthe spreader 32 (e.g., a single casting).

In the embodiment shown in FIG. 1, the spreader spring 34 is positionedbetween the spreader spring retainer 23 and the spreader 32. As can beseen in FIG. 1, a first end of the spreader spring 34 may be disposedagainst the spreader spring retainer 23, and a second end of thespreader spring 34 may be disposed against the spreader 32. The spreaderspring 34 is positioned such that when the spreader 32 slides along thelongitudinal shaft 22 towards the spreader spring retainer 23 (which maybe in an axially-fixed position relative to the spreader 32), thepotential energy in the spreader spring 34 is increased (and thereby theforce acting on the spreader spring retainer 23 and the spreader 32 isincreased). When the spreader 32 moves away from the rim 28 of the body21 and creates the annular opening 38, the spreader spring 34 may bebiased towards pushing the spreader 32 back towards the rim 28 of thebody 21 (i.e., the spreader 32 may be biased toward a closed positionand openable in response to boiler feedwater pressure at a deaeratorinlet 19). Therefore, in this embodiment, when the pressure from thefeedwater increases, the spreader 32 may be forced towards the spreaderspring retainer 23, such that the spreader 32 is disposed in an openposition, and when the pressure from the feedwater decreases, thespreader spring 34 may force the spreader 32 back towards the rim 28 ofthe body 21, such that the spreader 32 is disposed in a closed position.

Although in FIG. 1, the spreader spring 34 is depicted as a coil spring,in other embodiments, the spreader spring 34 may be replaced by anyspring mechanism or other mechanism that is capable of biasing thespreader 32 to be disposed in a closed position against the rim 28 ofthe body 21 when the feedwater pressure is below a desired thresholdlevel, while being capable of allowing the spreader 32 to be disposed inan open position, spaced apart form the rim 28 of the body 21 to definean annular opening 38, when the feedwater pressure exceeds a desiredthreshold level.

The annular opening 38 that is defined by the space between the spreader32 and the rim 28 of the body 21, when the spreader 32 is disposed in anopen position, may be of any diameter, height, and cross-sectional areathat is sufficient to allow the desired throughput of feedwater to passthrough the annular opening 38. The maximum surface area that is definedby the annular opening 38 will depend on the desired feedwaterthroughput speed and performance characteristics of the spray nozzleassembly and hub combination 10.

In the embodiment shown in FIGS. 1 and 2, the twist lock assembly 40 mayallow the spray nozzle assembly 12 to twist onto the hub 14. When thebody 21 of the spray nozzle assembly 12 is in a fully engaged positionin the hub 14, the body 21 may be retained relative to the hub 14, andthe spray nozzle assembly 12 may be secured relative to the hub 14.Referring to FIG. 1, the twist lock assembly 40 includes a lock spring42, pins 44, and slots (or grooves) 46. Referring to FIG. 2, each slot46 defines a open end 47 and a short leg 48. The short leg 48 of eachslot 46 has an end 49.

In the embodiment shown in FIGS. 1 and 2, the twist lock assembly 40 ispreferably actuated by the performance of a three-step actuationprocess. During the first insertion step, a user (not shown) places ahand on the handle 24 and applies a force approximately in a directionD1 that moves the spray nozzle assembly 12 in a direction D1 towards thehub 14, making sure to align the pins 44 with the open ends 47 of therespective slots 46. As the spray nozzle assembly 12 continues to movein the direction D1, the pins 44 enter the slots 46 via the respectiveopen ends 47. During the first insertion step, the lock spring 42 iscompressed, and the potential energy of the lock spring 42 increases asthe spray nozzle assembly 12 continues to move in the direction D1(i.e., the lock spring 42 is biased against insertion of the body 21 ofthe spray nozzle assembly 12 into the hub 14).

During the second twist step, the user preferably twists the handle 24in a rotational direction R2 (which may be clockwise orcounterclockwise), which moves the pins 44 through the correspondingslots 46 in a corresponding direction D2. During the third engagementstep, the user preferably reduces the force that was applied in thedirection D1, thereby allowing the lock spring 42 to push the body 21 ina direction D3, causing the pins 44 to slide along the correspondingshort legs 48 until the pins 44 come to rest against the correspondingends 49. When the pins 44 reach the corresponding ends 49, the body 21of the spray nozzle assembly 12 is in a fully engaged position in thehub 14. While the body 21 is in the fully engaged position in the hub14, the lock spring 42 continues to exert a force against the body 21 inthe direction D3, which allows the body 21 to be retained in positionwith the pins 44 against the corresponding ends 49, such that the spraynozzle assembly and hub combination 10 may be operated as intended in aboiler feedwater deaerator (not shown).

In order to remove the spray nozzle assembly 12 from the hub 14, thetwist lock assembly 40 is preferably actuated by the performance of athree-step removal process, during which the pins 44 are moved in thereverse directions from that of the actuation process. During the firstdisengagement step, the user preferably places a hand on the handle 24and applies a force approximately in a direction opposite that of thedirection D3 that moves the spray nozzle assembly 12 in the directionopposite that of the direction D3, thereby increasing the potentialenergy of the lock spring 42. During the second untwist step, the userpreferably twists the handle 24 in a rotational direction opposite therotational direction R2, which moves the pins 44 through thecorresponding slots 46 in a corresponding direction opposite thedirection D2. During the third withdrawal step, the user preferablyreduces the force that was applied in the direction opposite thedirection D3, thereby allowing the lock spring 42 to push the body 21 ina direction opposite the direction D1, causing the pins 44 to slidealong the slots 46 until the pins 44 exit the respective slots 46 viathe respective open ends 47 and causing the body 21 to exit the hub 14,thereby completing the removal of the spray nozzle assembly 12 from thehub 14.

In some embodiments (not shown), a method of installing a spray nozzleassembly 12 into a boiler feedwater deaerator (not shown) may includethe step of accessing the interior of a deaerator tank (not shown), inwhich a user or an installer (not shown) may access the tank interior byreaching through an access port (not shown), preferably without theinstaller's trunk entering into the tank interior. In some embodiments,some or all of the steps in the actuation process or the removal process(e.g., the insertion step and the twist step) may be performed by aninstaller's one hand without tools.

In the embodiment shown in FIG. 1, the lock spring 42 is positionedbetween the body 21 and the retaining surface 18 of the hub 14. As canbe seen in FIG. 1, a first end of the lock spring 42 may be disposed inthe circumferential spring groove 27 b, and a second end of the lockspring 42 may be disposed against the retaining surface 18 of the hub14. The lock spring 42 is positioned such that when the body 21 slidesin a direction D1 inside the hub 14 towards the retaining surface 18,the potential energy in the lock spring 42 is increased (and thereby theforce acting on the body 21 and the retaining surface 18 is increased).The lock spring 42 may be biased towards pushing the body 21 away fromthe retaining surface 18 of the hub 14, such that the bias of the lockspring 42 may assist the body 21 to be retained in a fully engagedposition in the hub 14.

Although in FIG. 1, the lock spring 42 is depicted as a coil spring, inother embodiments, the lock spring 42 may be replaced by any springmechanism or other mechanism that is capable of biasing the body 21 tobe retained in a fully engaged position in the hub 14, while beingcapable of allowing a typical user to overcome the bias force of thelock spring 42 during the actuation process and removal process.

The pins 44 and corresponding slots 46 of the twist lock assembly 40 mayprovide a mechanism to control the motion of the body 21 of the spraynozzle assembly 12 during actuation and removal of the body 21 into thehub 14. In the embodiment shown in FIG. 1, the length of each pin 44 isgreater than the thickness of the sidewalls of the hub 14. However, inother embodiments (not shown), the length of each pin 44 may be equal toor less than the thickness of the sidewalls of the hub 14. The exactlength of each pin 44 may be determined based on the desired ease ofalignment of the pins 44 with the respective slots 46, the desiredstrength of the pins 44, the particular design of the shape of the slots46, or other design or performance factors of the spray nozzle assemblyand hub combination 10.

As can be seen in FIG. 2, the diameter of each pin 44 is sized to beapproximately the same size or smaller than the width of thecorresponding slots 46. In the embodiment shown in FIG. 2, thecross-sectional profile of each pin 44 is generally circular. However,in other embodiments (not shown), the cross-sectional profile of eachpin 44 may be ovoid, square, rectangular, hexagonal, semi-circular, orany other shape the imparts the desired strength to the pin 44 andimparts the desired type and ease of alignment of each pin 44 into thecorresponding slot 46. In the embodiment shown, each pin 44 has the samecross-sectional shape, but in other embodiments (not shown), eachindividual pin 44 may have a shape that is different than the other pins44 in a particular body 21.

In the embodiment shown in FIG. 1, there are two pins 44, eachcorresponding to a slot 46. However, in other embodiments (not shown),there may be any number of pins 44, including three, four, five, six,eight, ten, twelve, or any other number that imparts the desired ease ofalignment of the pins 44 with the respective slots 46, the desiredstrength of the pins 44, the particular design of the shape of the slots46, or other design or performance factors of the spray nozzle assemblyand hub combination 10.

In the embodiment shown in FIG. 1, the pins 44 are symmetricallyoriented about the cylindrical outer surface of the body 21. However, inother embodiments (not shown), the pins 44 may be asymmetricallyoriented about the outer surface of the body 21. In some embodiments,the asymmetry may allow extra space between the pins 44 for some otherprotrusion or feature in the outer surface of the body 21 or in theinner surface of the hub 14.

As can be seen in FIG. 1, each slot 46 may penetrate completely throughthe outer wall of the hub 14. However, in other embodiments (not shown),each slot 46 may be a groove in the inside surface of the outer wall ofthe hub 14 rather than a slot going completely through the outer wall ofthe hub 14. In other embodiments (not shown), each groove 46 maypenetrate to any depth through the outer wall of the hub 14. Theparticular depth of each groove 46 may depend on the desired strength ofthe pins 44, the particular design of the shape of the slots 46, orother design or performance factors of the spray nozzle assembly and hubcombination 10.

As can be seen in FIG. 2, each slot 46 may be a J-shaped slot (i.e.,shaped either like a letter J or a backwards letter J) that maypenetrate completely through the outer wall of the hub 14. However, inother embodiments (not shown), each slot 46 may have other shapes,including a T-shape, which may allow each slot 46 to have two short legs48 and two corresponding ends 49, thereby allowing the twist lockassembly 40 to be actuated by the performance of a three-step actuationprocess that includes a second twist step of the handle 24 in either arotational direction R2 or the reverse of the rotational direction R2(clockwise or counterclockwise), depending on the preference of the useror other design or performance considerations of the spray nozzleassembly and hub combination 10. In other embodiments (not shown), eachslot 46 may take any shape that allows the twist lock assembly 40 to beactuated by compression of a lock spring 42 or other equivalenttensioning component, twisting of the body 21, and engagement of thepins 44 against respective ends 49 or other equivalent structures.

As can be seen in FIG. 2, each slot 46 comprises three straight legs,each successive leg oriented at approximately 90 degrees to the previousleg. In other embodiments (not shown), there may be two legs in aV-shape, four or more legs in a W-shape, three or more legs with eachleg oriented at 30 degrees, 45 degrees, 60 degrees, or any other angleto the previous leg, or any number of legs in any shape that allows thetwist lock assembly 40 to be actuated by compression of a lock spring 42or other equivalent tensioning component, twisting of the body 21, andengagement of the pins 44 against respective ends 49 or other equivalentstructures.

As can be seen in FIG. 2, each slot 46 may span 15 to 45 degrees of thetotal circumference of the outer wall of the hub 14. However, in otherembodiments (not shown), each slot 46 may span any portion of the totalcircumference of the outer wall of the hub 14, including five degrees,30 degrees, 60 degrees, 90 degrees, 120 degrees, and 150 degrees, or anyother circumferential span that allows the twist lock assembly 40 to beactuated by compression of a lock spring 42 or other equivalenttensioning component, twisting of the body 21, and engagement of thepins 44 against respective ends 49 or other equivalent structures.

In the embodiment shown in FIGS. 1 and 2, the length of the spray nozzleassembly and hub combination 10 in the direction D1 is approximately 9inches, the length of the body 21 in the direction D1 is approximately 3inches, the length of the hub 14 in the direction D1 is approximately 5inches, and the body 21 protrudes out of the hub 14 by approximately0.25 inches in the direction D1 when the body 21 is in the fully engagedposition in the hub 14. However, in other embodiments (not shown), thecomponents of the spray nozzle assembly and hub combination 10 may beany absolute size or any size relative to each other, depending on thedesign or performance requirements of the spray nozzle assembly and hubcombination 10.

All of the components of the spray nozzle assembly and hub combination10, except for the O-ring 25 and the spreader bushing 36, are preferablymade from steel, aluminum, or any other material known in the art havingenough strength and durability for use in a boiler feedwater deaeratorapplication. The O-ring 25 may be made from rubber or any other suitablematerial for water and pressure sealing that is known in the art. Thespreader bushing 36 may be made from plastic, Teflon, a metal such assteel or aluminum, or any other suitable material for water and pressuresealing that is known in the art. The various components of the spraynozzle assembly and hub combination 10 may also be coated with anymaterial suitable for protection from oxidation or other corrosion thatmay occur in such a boiler feedwater deaerator environment, such as zincor any other suitable material known in the art.

The foregoing description is provided for the purpose of explanation andis not to be construed as limiting the invention. While the inventionhas been described with reference to preferred embodiments or preferredmethods, it is understood that the words which have been used herein arewords of description and illustration, rather than words of limitation.Furthermore, although the invention has been described herein withreference to particular structure, methods, and embodiments, theinvention is not intended to be limited to the particulars disclosedherein, as the invention extends to all structures, methods and usesthat are within the scope of the appended claims. Further, severaladvantages have been described that flow from the structure and methods;the present invention is not limited to structure and methods thatencompass any or all of these advantages. Those skilled in the relevantart, having the benefit of the teachings of this specification, mayeffect numerous modifications to the invention as described herein, andchanges may be made without departing from the scope and spirit of theinvention as defined by the appended claims.

1. A method of installing a spray nozzle assembly into a boilerfeedwater deaerator comprising the steps of: accessing an interior of adeaerator tank; providing a spray nozzle assembly that includes a lockfeature, a nozzle body, and a spreader that is biased toward a closedposition and openable in response to boiler feedwater pressure at adeaerator inlet; inserting at least a portion of the spray nozzleassembly into a hub affixed to the deaerator against bias of a spring;and twisting the spray nozzle assembly relative to the hub to engage thelock feature to secure the spray nozzle assembly relative to the hub. 2.The method of claim 1 wherein the lock feature is a pin that extendsfrom the nozzle body that engages with a corresponding groove in thehub.
 3. The method of claim 2 wherein the groove is an inverted J-shapesuch that when the spray nozzle assembly is in an installed position atthe completion of the twisting step, the spring biases the pin againstan end of a short leg of the J-shaped groove.
 4. The method of claim 1wherein the inserting step and the twisting step may be performed by aninstaller's one hand without tools.
 5. The method of claim 1 wherein theaccessing step consists of an installer accessing the tank interior byreaching through an access port without the installer's trunk enteringinto the tank interior.